1. Field
Embodiments of the present invention relate to a charger for electric vehicles, which has a wide output voltage range.
2. Description of the Related Art
Serious global pollution is increasing the importance of using pollution-free energy. In particular, air pollution in major cities is getting worse and one cause thereof is exhaust fumes of vehicles.
In this situation, a study to commercialize so-called electric vehicles whose power source is electricity that is pollution-free energy is actively being progressed. Electric vehicles charge a battery with electric energy supplied from an external station, and obtain mechanical energy from the charged battery voltage via a motor coupled to vehicle wheels.
Thus, to drive the motor using the charged battery voltage, the electric vehicles include a high-capacity rechargeable battery and a battery charger to charge the high-capacity rechargeable battery.
Battery chargers are classified into a fast charger and a slow charger based on charging time. The fast charger is installed at a place for immediate charging during traveling, such as a filling station, and takes about 20 minutes to charge. On the other hand, the slow charger is installed at a place where long-term parking is expected, such as a parking lot or shopping mall, and takes about 5 hours to charge.
These battery chargers are not designed to use all AC input voltages, i.e. commercial voltages of 110V/220V, but designed to use a single AC input voltage, and have a narrow output voltage range upon charging.